1. Field of the Invention
This invention relates to apparatus for reducing the wind resistance or drag effecting the movement of vehicles through a fluid, and more particularly to drag reduction in cargo carrying vehicles such as single chassis trucks, tractor trailers and cars with trailers in tow wherein the trailer or cargo body extends above the cab or roof of the truck or car.
2. Discussion of the Prior Art
The box-like structures which are utilized to carry cargo unfortunately create high drag or wind resistance when being pulled along the highways. In an attempt to reduce this drag, many patents have been granted for apparatus which are designed to reduce the air resistance. For example, the following U.S. Patents illustrate tractor trailer or automobile and trailer combinations wherein a wind deflector of one type or another is placed on top of the cab of the tractor or the roof of the automobile in order to reduce the drag produced by the wind engaging the flat upper front portion of the trailer or cargo body which is exposed above the top or roof of the cab or automobile.
______________________________________ U.S. Pat. No. 2,863,695 Stamm U.S. Pat. No. 3,241,876 Saunders U.S. Pat. No. 3,309,131 Saunders U.S. Pat. No. 3,348,873 Saunders U.S. Pat. No. 3,596,974 Adams ______________________________________
However, in each of these disclosures, the wind deflector in the first instance is not as high as the top of the trailer and secondly, there is a large space or gap provided between the wind deflector and the front of the trailer. This causes a great amount of turbulence between the wind deflector and the trailer front or cargo body front, on unitary chassis trucks, (hereinafter also commonly referred to as a trailer), and accordingly, the wind drag resistance is not materially reduced. In addition, such a wind deflector does not tend to stabilize the trailer when it is traveling at higher speeds.
U.S. Pat. No. 3,697,120 issued to Saunders, illustrates a drag reducer which is attached directly to the front of the trailer. This structure tends to stabilize the trailer, however, it does not materially reduce the drag resistance as major flat front portions of the trailer are still exposed directly to the high speed winds. In addition, a large gap still exists between the front of the trailer and the back of the cab such that the wind is permitted to flow down into this gap with a great amount of turbulence thereby increasing the drag and reducing stability.
Another patent of interest is U.S. Pat. No. 2,914,231 issued to W. L. Hornke for a luggage carrier which utilizes a V-shaped front for deflecting the wind. However, the Hornke structure, while assisting in drag resistance to a luggage rack, does not truly split the wind for stabilization purposes, and in addition does not teach how such principles might be applied to tractor trailers, automobiles with tractors in tow and single chassis trucks.